1. Field of the Invention
The invention relates to a conveyor system that transports a plurality of pallets.
2. Description of Related Art
A conveyor system that transports a pallet on which a work piece is mounted is, for example, described in Japanese Patent Application Publication No. 2009-166936 (JP-A-2009-166936).
The technique described in JP-A-2009-166936 is used to transport a pallet on which a work piece is mounted. The conveyor system described in JP-A-2009-166936 includes a direct drive feed mechanism, pins that are moved by the direct drive feed mechanism, an engaging/disengaging mechanism that engages the pins with or disengages the pins from the pallet, and the like.
With the above conveyor system, the pallet may be transported in such a manner that the pins are moved by the direct drive feed mechanism toward the downstream side in a pallet transport direction in a state where the pins are engaged with the pallet. After the pins move toward the downstream side in the transport direction with the pins engaged with the pallet to transport the pallet, the pins disengage from the pallet and move toward the upstream side in the transport direction, and then engage with a pallet again and move toward the downstream side in the transport direction to transport the pallet. In this way, the pins are reciprocally moved in the transport direction while the pins are engaged with or disengaged from a pallet to thereby intermittently transport a pallet. However, the technique described in JP-A-2009-166936 is configured so that the pair of pins are reciprocally moved in the pallet transport direction to intermittently transport a pallet, so that the technique cannot be used in a system that transports a pallet at a constant speed (for example, an engine assembly line, or the like). In addition, when the length of the conveyor system is changed, it is necessary to adapt the direct drive feed mechanism, the engaging/disengaging mechanism, etc. to the changed length. Thus, man-hours required to change the length increase.
The conveyor system that is configured to transport a pallet at a constant speed is, for example, a conveyor system 110 that includes drive transmitting portions 130, each of which transmits the power of a corresponding one of motors 120, as shown in FIG. 9A and FIG. 9B. The conveyor system 110 is configured so that a plurality of transport mechanisms are arranged in the transport direction, and the motor 120 and the drive transmitting portion 130 are provided for each transport mechanism. A rotary shaft of each motor 120 is coupled to corresponding rollers 140 via gears 131 of the drive transmitting portion 130, a shaft 132, etc. The rollers 140 are driven by the corresponding motor 120 in each transport mechanism. In this way, the motors 120 and the drive transmitting portions 130, provided for each transport mechanism, are arranged along the length of the conveyor system 110, as shown in FIG. 10.
When the length of the thus configured conveyor system 110 is changed, work for wiring power lines 122 that transmit power to the respective motors 120, work for adjusting the drive transmitting portions 130, etc. are required. Thus, man-hours required to change the length of the conveyor system 110 increase. In addition, the power of each motor 120 is transmitted to the corresponding rollers 140 via many gears 131, etc., so that a power loss occurs during transmission of power. Thus, a high-power motor is employed in consideration of the power loss is required.